In recent years, apparatuses using heat energy obtained by condensing sunlight onto a predetermined position as environment-friendly clean energy have been briskly developed.
As an optical condenser that condenses sunlight onto a predetermined position, for example, there is an apparatus described in the following PTL 1. This optical condenser includes a mirror and a driving device that turns the mirror around two rotational axes having mutually different orientations. In this optical condenser, one rotational axis of the two rotational axes is set to be parallel to the earth's axis. That is, in this optical condenser, an equatorial telescope type is adopted as the driving device.